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dosbox-staging/src/hardware/gus.cpp
Sjoerd van der Berg 31fe898cf5 Add 32bit internal mixing 
Speed it up a bit
Clean it up a bit


Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@1833
2004-06-14 11:46:32 +00:00

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/*
* Copyright (C) 2002-2004 The DOSBox Team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <string.h>
#include "dosbox.h"
#include "inout.h"
#include "mixer.h"
#include "dma.h"
#include "pic.h"
#include "setup.h"
#include "programs.h"
#include "math.h"
#include "regs.h"
#define GUS_BASE myGUS.portbase
#define GUS_RATE myGUS.rate
#define LOG_GUS
static MIXER_Channel * gus_chan;
static Bit16u vol8bit[256];
static Bit16s vol16bit[4096];
static Bit8u irqtable[8] = { 0, 2, 5, 3, 7, 11, 12, 15 };
static Bit8u dmatable[6] = { 3, 1, 5, 5, 6, 7 };
static Bit8u GUSRam[1024*1024]; // 1024K of GUS Ram
static Bit32s AutoAmp=1024;
Bit8u adlib_commandreg;
struct GFGus {
Bit8u gRegSelect;
Bit16u gRegData;
Bit32u gDramAddr;
Bit16u gCurChannel;
Bit8u DMAControl;
Bit16u dmaAddr;
Bit8u TimerControl;
Bit8u SampControl;
Bit8u mixControl;
Bit32u basefreq;
Bit16u activechan;
Bit32s mupersamp;
Bit32s muperchan;
struct GusTimer {
Bit16u bytetimer;
Bit32s countdown;
Bit32s setting;
bool active;
} timers[2];
Bit32u rate;
Bit16u portbase;
Bit16u dma1;
Bit16u dma2;
Bit16u irq1;
Bit16u irq2;
char ultradir[512];
bool irqenabled;
// IRQ status register values
struct IRQStat {
bool MIDITx;
bool MIDIRx;
bool T1;
bool T2;
bool Resv;
bool WaveTable;
bool VolRamp;
bool DMATC;
} irq;
} myGUS;
#define GUSFIFOSIZE 1024
struct IRQFifoEntry {
Bit8u channum;
bool WaveIRQ;
bool RampIRQ;
};
struct IRQFifoDef {
IRQFifoEntry entry[GUSFIFOSIZE];
Bit16s stackpos;
} IRQFifo;
static void GUS_DMA_Callback(DmaChannel * chan,DMAEvent event);
// Routines to manage IRQ requests coming from the GUS
static void pushIRQ(Bit8u channum, bool WaveIRQ, bool RampIRQ) {
IRQFifo.stackpos++;
if(IRQFifo.stackpos < GUSFIFOSIZE) {
myGUS.irq.WaveTable = WaveIRQ;
myGUS.irq.VolRamp = RampIRQ;
IRQFifo.entry[IRQFifo.stackpos].channum = channum;
IRQFifo.entry[IRQFifo.stackpos].RampIRQ = RampIRQ;
IRQFifo.entry[IRQFifo.stackpos].WaveIRQ = WaveIRQ;
} else {
LOG_GUS("GUS IRQ Fifo full!");
}
}
static void popIRQ(IRQFifoEntry * tmpentry) {
if(IRQFifo.stackpos<0) {
tmpentry->channum = 0;
tmpentry->RampIRQ = false;
tmpentry->WaveIRQ = false;
return;
}
memcpy(tmpentry, &IRQFifo.entry[IRQFifo.stackpos], sizeof(IRQFifoEntry));
--IRQFifo.stackpos;
if(IRQFifo.stackpos >= 0) {
myGUS.irq.WaveTable = IRQFifo.entry[IRQFifo.stackpos].WaveIRQ;
myGUS.irq.VolRamp = IRQFifo.entry[IRQFifo.stackpos].RampIRQ;
} else {
myGUS.irq.WaveTable = false;
myGUS.irq.VolRamp = false;
}
}
// Returns a single 16-bit sample from the Gravis's RAM
static INLINE Bit32s GetSample(Bit32u Delta, Bit32u CurAddr, bool eightbit) {
Bit32u useAddr;
Bit32u holdAddr;
useAddr = CurAddr >> 9;
if(eightbit) {
if(Delta >= 1024) {
Bit32s tmpsmall = (Bit8s)GUSRam[useAddr];
// return tmpsmall << 7;
return tmpsmall << 8;
} else {
// Interpolate
Bit32s w1 = ((Bit8s)GUSRam[useAddr+0]) << 8;
Bit32s w2 = ((Bit8s)GUSRam[useAddr+1]) << 8;
Bit32s diff = w2 - w1;
return (w1+((diff*(Bit32s)(CurAddr&511))>>9));
}
} else {
// Formula used to convert addresses for use with 16-bit samples
holdAddr = useAddr & 0xc0000L;
useAddr = useAddr & 0x1ffffL;
useAddr = useAddr << 1;
useAddr = (holdAddr | useAddr);
if(Delta >= 1024) {
// return (GUSRam[useAddr+0] | (((Bit8s)GUSRam[useAddr+1]) << 8)) >> 2;
return (GUSRam[useAddr+0] | (((Bit8s)GUSRam[useAddr+1]) << 8));
} else {
// Interpolate
Bit32s w1 = (GUSRam[useAddr+0] | (((Bit8s)GUSRam[useAddr+1]) << 8));
Bit32s w2 = (GUSRam[useAddr+2] | (((Bit8s)GUSRam[useAddr+3]) << 8));
Bit32s diff = w2 - w1;
return (w1+((diff*(Bit32s)(CurAddr&511))>>9));
}
}
}
class GUSChannels {
public:
Bit8u voiceCont;
Bit16u FreqCont;
Bit32u RealDelta;
Bit32u StartAddr;
Bit32u EndAddr;
Bit8s VolRampRate;
Bit16s VolRampStart;
Bit16s VolRampEnd;
Bit8u VolRampStartOrg;
Bit8u VolRampEndOrg;
Bit32s CurVolume;
Bit32u CurAddr;
Bit8u PanPot;
Bit8u VolControl;
Bit8u channum;
bool moving;
bool playing;
bool ramping;
bool dir;
bool voldir;
public:
bool notifyonce;
Bit32s leftvol;
Bit32s rightvol;
Bit32s nextramp;
GUSChannels(Bit8u num) {
channum = num;
playing = true;
ramping = false;
moving = false;
dir = false;
voldir = false;
StartAddr = 0;
EndAddr = 0;
CurAddr = 0;
VolRampRate = 0;
VolRampStart = 0;
VolRampEnd = 0;
leftvol = 255;
rightvol = 255;
nextramp = 0;
};
// Voice control register
void WriteVoiceCtrl(Bit8u val) {
voiceCont = val;
if (val & 0x3) moving = false;
if ((val & 0x3) == 0) {
//playing = true;
moving = true;
}
dir = false;
if((val & 0x40) !=0) dir = true;
}
Bit8u ReadVoiceCtrl(void) {
Bit8u tmpval = voiceCont & 0xfe;
if(!playing) tmpval++;
return tmpval;
}
// Frequency control register
void WriteFreqCtrl(Bit16u val) {
FreqCont = val;
int fc;
fc = val;
fc = fc >> 1;
fc = fc * myGUS.basefreq;
fc = fc - (myGUS.basefreq >> 1);
fc = fc / 512;
float simple;
simple = ((float)fc / (float)GUS_RATE) * 512;
RealDelta = (Bit32u)simple;
}
Bit16u ReadFreqCtrl(void) {
return FreqCont;
}
// Used when GUS changes channel numbers during playback
void UpdateFreqCtrl() { WriteFreqCtrl(FreqCont); }
// Pan position register
void WritePanPot(Bit8u val) {
if(val<8) {
leftvol = 255;
rightvol = val << 5;
} else {
rightvol = 255;
leftvol = (8-(val-8)) << 5;
}
PanPot = val;
}
Bit8u ReadPanPot(void) {
return PanPot;
}
// Volume ramping control register
void WriteVolControl(Bit8u val) {
VolControl = val;
if (val & 0x3) ramping = false;
if ((val & 0x3) == 0) ramping = true;
voldir = false;
if((val & 0x40) !=0) voldir = true;
}
Bit8u ReadVolControl(void) {
Bit8u tmpval = VolControl & 0xfe;
if(!ramping) tmpval++;
return tmpval;
}
// Methods to queue IRQ on ramp or sample end
void NotifyEndSamp(void) {
if(!notifyonce) {
if((voiceCont & 0x20) != 0) {
pushIRQ(channum,true,false);
notifyonce = true;
}
}
}
void NotifyEndRamp(void) {
if(!notifyonce) {
if((VolControl & 0x20) != 0) {
pushIRQ(channum,false,true);
notifyonce = true;
}
}
}
// Debug routine to show current channel position
void ShowAddr(void) {
LOG_GUS("Chan %d Start %d End %d Current %d", channum, StartAddr>>9, EndAddr>>9, CurAddr>>9);
}
// Generate the samples required by the callback routine
// It should be noted that unless a channel is stopped, it will
// continue to return the sample it is pointing to, regardless
// of whether or not the channel is moving or ramping.
void generateSamples(Bit32s * stream,Bit32u len) {
int i;
Bit32s tmpsamp;
bool eightbit;
eightbit = ((voiceCont & 0x4) == 0);
notifyonce = false;
for(i=0;i<(int)len;i++) {
// Get sample
tmpsamp = GetSample(RealDelta, CurAddr, eightbit);
// Clip and convert log scale to PCM scale
if(CurVolume>4095) CurVolume = 4095;
if(CurVolume<0) CurVolume = 0;
tmpsamp = (tmpsamp * vol16bit[CurVolume]) >> 12;
// Output stereo sample
stream[i<<1]+= tmpsamp * leftvol;
stream[(i<<1)+1]+= tmpsamp * rightvol;
if (dir) {
// Increment backwards but don't let it get below zero.
if (moving) { if(CurAddr > RealDelta) CurAddr -= RealDelta; else CurAddr = 0; }
//Thought 16-bit needed this
//if ((!eightbit) && (moving)) CurAddr -= RealDelta;
if(CurAddr <= StartAddr) {
if((VolControl & 0x4) == 0) {
if((voiceCont & 0x8) != 0) {
if((voiceCont & 0x10) != 0) {
dir = !dir;
} else {
CurAddr = EndAddr - (512-(CurAddr & 511));
}
} else {
moving = false;
}
NotifyEndSamp();
} else {
NotifyEndSamp();
}
}
} else {
// Increment forwards
if (moving) CurAddr += RealDelta;
//Thought 16-bit needed this
//if ((!eightbit) && (moving)) CurAddr += RealDelta;
if(CurAddr >= EndAddr) {
if((VolControl & 0x4) == 0) {
if((voiceCont & 0x8) != 0) {
if((voiceCont & 0x10) != 0) {
dir = !dir;
} else {
CurAddr = StartAddr+(CurAddr & 511);
}
} else {
moving = false;
}
NotifyEndSamp();
} else {
NotifyEndSamp();
}
}
}
// Update volume
if(ramping) {
// Subtract ramp counter by elapsed microseconds
nextramp -= myGUS.mupersamp;
bool flagged;
flagged = false;
// Ramp volume until nextramp is a positive integer
while(nextramp <= 0) {
if(voldir) {
CurVolume -= (VolRampRate & 0x3f);
if (CurVolume <= 0) {
CurVolume = 0;
flagged = true;
}
if((vol16bit[CurVolume]<=VolRampStart) || (flagged)){
if((VolControl & 0x8) != 0) {
if((VolControl & 0x10) != 0) {
voldir = !voldir;
} else {
CurVolume = VolRampEndOrg;
}
} else {
ramping = false;
}
NotifyEndRamp();
}
} else {
CurVolume += (VolRampRate & 0x3f);
if (CurVolume >= 4095) {
CurVolume = 4095;
flagged = true;
}
if((vol16bit[CurVolume]>=VolRampEnd) || (flagged)){
if((VolControl & 0x8) != 0) {
if((VolControl & 0x10) != 0) {
voldir = !voldir;
} else {
CurVolume = VolRampStartOrg;
}
} else {
ramping = false;
}
NotifyEndRamp();
}
}
#if 1
static Bit32u rampmultable[4]={1,8,64,512};
nextramp += myGUS.muperchan*rampmultable[VolRampRate >> 6];
#else
switch(VolRampRate >> 6) {
case 0:
nextramp += myGUS.muperchan;
break;
case 1:
nextramp += myGUS.muperchan* 8;
break;
case 2:
nextramp += myGUS.muperchan * 64;
break;
case 3:
nextramp += myGUS.muperchan * 512;
break;
default:
nextramp += myGUS.muperchan * 512;
break;
}
#endif
}
}
}
}
};
GUSChannels *guschan[33];
GUSChannels *curchan;
static void GUSReset(void)
{
if((myGUS.gRegData & 0x1) == 0x1) {
// Reset
adlib_commandreg = 85;
memset(&myGUS.irq, 0, sizeof(myGUS.irq));
}
if((myGUS.gRegData & 0x4) != 0) {
myGUS.irqenabled = true;
} else {
myGUS.irqenabled = false;
}
myGUS.timers[0].active = false;
myGUS.timers[1].active = false;
myGUS.timers[0].bytetimer = 0x0;
myGUS.timers[1].bytetimer = 0x0;
// Stop all channels
int i;
for(i=0;i<32;i++) {
guschan[i]->WriteVoiceCtrl(0x3);
}
IRQFifo.stackpos = -1;
}
static Bit16u ExecuteReadRegister(void) {
Bit8u tmpreg;
switch (myGUS.gRegSelect) {
case 0x41: // Dma control register - read acknowledges DMA IRQ
tmpreg = myGUS.DMAControl & 0xbf;
if(myGUS.irq.DMATC) tmpreg |= 0x40;
myGUS.irq.DMATC = false;
PIC_DeActivateIRQ(myGUS.irq1);
return (Bit16u)(tmpreg << 8);
case 0x42: // Dma address register
return myGUS.dmaAddr;
case 0x45: // Timer control register. Identical in operation to Adlib's timer
return (Bit16u)(myGUS.TimerControl << 8);
break;
case 0x49: // Dma sample register
tmpreg = myGUS.DMAControl & 0xbf;
if(myGUS.irq.DMATC) tmpreg |= 0x40;
myGUS.irq.DMATC = false;
PIC_DeActivateIRQ(myGUS.irq1);
//LOG_GUS("Read sampling status, returned 0x%x", tmpreg);
return (Bit16u)(tmpreg << 8);
case 0x80: // Channel voice control read register
if(curchan != NULL) {
Bit8u sndout;
sndout = curchan->voiceCont & 0xFC;
if(!curchan->moving) sndout |= 0x3;
return (Bit16u)(sndout<< 8);
} else return 0x0300;
case 0x82: // Channel MSB address register
if(curchan != NULL) {
return (Bit16u)(curchan->StartAddr >> 16);
} else return 0x0000;
case 0x83: // Channel LSW address register
if(curchan != NULL) {
return (Bit16u)(curchan->StartAddr & 0xffff);
} else return 0x0000;
case 0x89: // Channel volume register
if(curchan != NULL) {
return ((Bit16u)curchan->CurVolume << 4);
} else return 0x0000;
case 0x8a: // Channel MSB current address register
if(curchan != NULL) {
return (Bit16u)(curchan->CurAddr >> 16);
} else return 0x0000;
case 0x8b: // Channel LSW current address register
if(curchan != NULL) {
return (Bit16u)(curchan->CurAddr & 0xFFFF);
} else return 0x0000;
case 0x8d: // Channel volume control register
if(curchan != NULL) {
Bit8u volout;
volout = curchan->VolControl & 0xFC;
if(!curchan->ramping) volout |= 0x3;
return (volout << 8);
} else return 0x0300;
case 0x8f: // General channel IRQ status register
Bit8u temp;
temp = 0x20;
IRQFifoEntry tmpentry;
PIC_DeActivateIRQ(myGUS.irq1);
popIRQ(&tmpentry);
if(!tmpentry.WaveIRQ) temp |= 0x80;
if(!tmpentry.RampIRQ) temp |= 0x40;
temp |= tmpentry.channum;
return (Bit16u)(temp << 8);
default:
LOG_GUS("Read Register num 0x%x", myGUS.gRegSelect);
return myGUS.gRegData;
}
}
static void ExecuteGlobRegister(void) {
int i;
//LOG_GUS("Access global register %x with %x", myGUS.gRegSelect, myGUS.gRegData);
switch(myGUS.gRegSelect) {
case 0x0: // Channel voice control register
if(curchan != NULL) {
curchan->WriteVoiceCtrl((Bit16u)myGUS.gRegData>>8);
}
break;
case 0x1: // Channel frequency control register
if(curchan != NULL) {
curchan->WriteFreqCtrl(myGUS.gRegData);
}
break;
case 0x2: // Channel MSB start address register
if(curchan != NULL) {
Bit32u tmpaddr = myGUS.gRegData << 16;
curchan->StartAddr = (curchan->StartAddr & 0xFFFF) | tmpaddr;
}
break;
case 0x3: // Channel LSB start address register
if(curchan != NULL) {
Bit32u tmpaddr = (Bit32u)(myGUS.gRegData);
curchan->StartAddr = (curchan->StartAddr & 0x1FFF0000) | tmpaddr;
}
break;
case 0x4: // Channel MSB end address register
if(curchan != NULL) {
Bit32u tmpaddr = (Bit32u)myGUS.gRegData << 16;
curchan->EndAddr = (curchan->EndAddr & 0xFFFF) | tmpaddr;
}
break;
case 0x5: // Channel MSB end address register
if(curchan != NULL) {
Bit32u tmpaddr = (Bit32u)(myGUS.gRegData);
curchan->EndAddr = (curchan->EndAddr & 0x1FFF0000) | tmpaddr;
}
break;
case 0x6: // Channel volume ramp rate register
if(curchan != NULL) {
Bit8u tmpdata = (Bit16u)myGUS.gRegData>>8;
curchan->VolRampRate = tmpdata;
}
break;
case 0x7: // Channel volume ramp start register EEEEMMMM
if(curchan != NULL) {
Bit8u tmpdata = (Bit16u)myGUS.gRegData >> 8;
curchan->VolRampStart = vol8bit[tmpdata];
curchan->VolRampStartOrg = tmpdata << 4;
}
break;
case 0x8: // Channel volume ramp end register EEEEMMMM
if(curchan != NULL) {
Bit8u tmpdata = (Bit16u)myGUS.gRegData >> 8;
curchan->VolRampEnd = vol8bit[tmpdata];
curchan->VolRampEndOrg = tmpdata << 4;
}
break;
case 0x9: // Channel current volume register
if(curchan != NULL) {
Bit16u tmpdata = (Bit16u)myGUS.gRegData >> 4;
curchan->CurVolume = tmpdata;
}
break;
case 0xA: // Channel MSB current address register
if(curchan != NULL) {
Bit32u tmpaddr = ((Bit32u)myGUS.gRegData & 0x1fff) << 16;
curchan->CurAddr = (curchan->CurAddr & 0xFFFF) | tmpaddr;
}
break;
case 0xB: // Channel LSW current address register
if(curchan != NULL) {
curchan->CurAddr = (curchan->CurAddr & 0xFFFF0000) | ((Bit32u)myGUS.gRegData);
}
break;
case 0xC: // Channel pan pot register
if(curchan != NULL) {
curchan->WritePanPot((Bit16u)myGUS.gRegData>>8);
}
break;
case 0xD: // Channel volume control register
if(curchan != NULL) {
curchan->WriteVolControl((Bit16u)myGUS.gRegData>>8);
}
break;
case 0xE: // Set active channel register
myGUS.activechan = (myGUS.gRegData>>8) & 63;
if(myGUS.activechan < 13) myGUS.activechan = 13;
if(myGUS.activechan > 31) myGUS.activechan = 31;
MIXER_Enable(gus_chan,true);
myGUS.basefreq = (Bit32u)((float)1000000/(1.619695497*(float)(myGUS.activechan+1)));
float simple;
simple = (1.0f / (float)GUS_RATE) / 0.000001f;
myGUS.mupersamp = (Bit32s)simple*1024;
myGUS.muperchan = (Bit32s)((float)1.6 * (float)myGUS.activechan * 1024);
LOG_GUS("GUS set to %d channels", myGUS.activechan);
for(i=0;i<=myGUS.activechan;i++) { if(guschan[i] != NULL) guschan[i]->UpdateFreqCtrl(); }
break;
case 0x10: // Undocumented register used in Fast Tracker 2
break;
case 0x41: // Dma control register
myGUS.DMAControl = (Bit8u)(myGUS.gRegData>>8);
DmaChannels[myGUS.dma1]->Register_Callback(
(myGUS.DMAControl & 0x1) ? GUS_DMA_Callback : 0);
break;
case 0x42: // Gravis DRAM DMA address register
myGUS.dmaAddr = myGUS.gRegData;
break;
case 0x43: // MSB Peek/poke DRAM position
myGUS.gDramAddr = (0xff0000 & myGUS.gDramAddr) | ((Bit32u)myGUS.gRegData);
break;
case 0x44: // LSW Peek/poke DRAM position
myGUS.gDramAddr = (0xffff & myGUS.gDramAddr) | ((Bit32u)myGUS.gRegData>>8) << 16;
break;
case 0x45: // Timer control register. Identical in operation to Adlib's timer
myGUS.TimerControl = (Bit8u)(myGUS.gRegData>>8);
if((myGUS.TimerControl & 0x08) !=0) myGUS.timers[1].countdown = myGUS.timers[1].setting;
if((myGUS.TimerControl & 0x04) !=0) myGUS.timers[0].countdown = myGUS.timers[0].setting;
myGUS.irq.T1 = false;
myGUS.irq.T2 = false;
PIC_DeActivateIRQ(myGUS.irq1);
break;
case 0x46: // Timer 1 control
myGUS.timers[0].bytetimer = (Bit8u)(myGUS.gRegData>>8);
myGUS.timers[0].setting = ((Bit32s)0xff - (Bit32s)myGUS.timers[0].bytetimer) * ((Bit32s)80 << 10);
myGUS.timers[0].countdown = myGUS.timers[0].setting;
break;
case 0x47: // Timer 2 control
myGUS.timers[1].bytetimer = (Bit8u)(myGUS.gRegData>>8);
myGUS.timers[1].setting = ((Bit32s)0xff - (Bit32s)myGUS.timers[1].bytetimer) * ((Bit32s)360 << 10);
myGUS.timers[1].countdown = myGUS.timers[1].setting;
break;
case 0x49: // DMA sampling control register
myGUS.SampControl = (Bit8u)(myGUS.gRegData>>8);
DmaChannels[myGUS.dma1]->Register_Callback(
(myGUS.SampControl & 0x1) ? GUS_DMA_Callback : 0);
break;
case 0x4c: // GUS reset register
GUSReset();
break;
default:
LOG_GUS("Unimplemented global register %x -- %x", myGUS.gRegSelect, myGUS.gRegData);
}
return;
}
static Bitu read_gus(Bitu port,Bitu iolen) {
switch(port - GUS_BASE) {
case 0x206:
Bit8u temp;
temp = 0;
if(myGUS.irq.MIDITx) temp |= 1;
if(myGUS.irq.MIDIRx) temp |= 2;
if(myGUS.irq.T1) temp |= 4;
if(myGUS.irq.T2) temp |= 8;
if(myGUS.irq.Resv) temp |= 16;
if(myGUS.irq.WaveTable) temp |= 32;
if(myGUS.irq.VolRamp) temp |= 64;
if(myGUS.irq.DMATC) temp |= 128;
PIC_DeActivateIRQ(myGUS.irq1);
return temp;
case 0x208:
Bit8u tmptime;
tmptime = 0;
if(myGUS.irq.T1) tmptime |= (1 << 6);
if(myGUS.irq.T2) tmptime |= (1 << 5);
if((myGUS.irq.T1) || (myGUS.irq.T2)) tmptime |= (1 << 7);
return tmptime;
case 0x20a:
return adlib_commandreg;
case 0x302:
return (Bit8u)myGUS.gCurChannel;
case 0x303:
return myGUS.gRegSelect;
case 0x304:
if (iolen==2) return ExecuteReadRegister() & 0xffff;
else return ExecuteReadRegister() & 0xff;
case 0x305:
return ExecuteReadRegister() >> 8;
case 0x307:
if(myGUS.gDramAddr < sizeof(GUSRam)) {
return GUSRam[myGUS.gDramAddr];
} else {
return 0;
}
default:
LOG_GUS("Read GUS at port 0x%x", port);
break;
}
return 0xff;
}
static void write_gus(Bitu port,Bitu val,Bitu iolen) {
switch(port - GUS_BASE) {
case 0x200:
myGUS.mixControl = val;
break;
case 0x208:
adlib_commandreg = val;
break;
case 0x209:
//TODO adlib_commandreg should be 4 for this to work else it should just latch the value
myGUS.timers[0].active = ((val & 0x1) > 0);
myGUS.timers[1].active = ((val & 0x2) > 0);
break;
//TODO Check if 0x20a register is also available on the gus like on the interwave
case 0x20b:
if((myGUS.mixControl & 0x40) != 0) {
// IRQ configuration
Bit8u temp = val & 0x7; // Select GF1 irq
if(myGUS.irq1 == irqtable[temp]) {
} else {
LOG_GUS("Attempt to assign GUS to wrong IRQ - at %x set to %x", myGUS.irq1, irqtable[temp]);
}
} else {
// DMA configuration
Bit8u temp = val & 0x7; // Select playback IRQ
if(myGUS.dma1 == dmatable[temp]) {
} else {
LOG_GUS("Attempt to assign GUS to wrong DMA - at %x, assigned %x", myGUS.dma1, dmatable[temp]);
}
}
break;
case 0x302:
myGUS.gCurChannel = val ;
if (myGUS.gCurChannel > 32) myGUS.gCurChannel = 32;
curchan = guschan[val];
break;
case 0x303:
myGUS.gRegSelect = val;
myGUS.gRegData = 0;
break;
case 0x304:
if (iolen==2) myGUS.gRegData=val;
else myGUS.gRegData = (0xff00 & myGUS.gRegData) | val;
ExecuteGlobRegister();
break;
case 0x305:
myGUS.gRegData = (0x00ff & myGUS.gRegData) | val << 8;
ExecuteGlobRegister();
break;
case 0x307:
if(myGUS.gDramAddr < sizeof(GUSRam)) GUSRam[myGUS.gDramAddr] = val;
break;
default:
LOG_GUS("Write GUS at port 0x%x with %x", port, val);
break;
}
}
static void GUS_DMA_Callback(DmaChannel * chan,DMAEvent event) {
if (event!=DMA_UNMASKED) return;
Bitu dmaaddr = myGUS.dmaAddr << 4;
if((myGUS.DMAControl & 0x2) == 0) {
Bitu read=chan->Read(chan->currcnt+1,&GUSRam[dmaaddr]);
//Check for 16 or 8bit channel
read*=(chan->DMA16+1);
if((myGUS.DMAControl & 0x80) != 0) {
//Invert the MSB to convert twos compliment form
Bitu i;
if((myGUS.DMAControl & 0x40) == 0) {
// 8-bit data
for(i=dmaaddr;i<(dmaaddr+read);i++) GUSRam[i] ^= 0x80;
} else {
// 16-bit data
for(i=dmaaddr+1;i<(dmaaddr+read-1);i+=2) GUSRam[i] ^= 0x80;
}
}
} else {
//Read data out of UltraSound
chan->Write(chan->currcnt+1,&GUSRam[dmaaddr]);
}
/* Raise the TC irq if needed */
if((myGUS.DMAControl & 0x20) != 0) {
myGUS.irq.DMATC = true;
PIC_ActivateIRQ(myGUS.irq1);
}
chan->Register_Callback(0);
}
static void GUS_CallBack(Bit8u * stream,Bit32u len) {
Bit32s buffer[4096];
memset(&buffer[0],0,len*8);
Bitu i;
for(i=0;i<=myGUS.activechan;i++) {
if (guschan[i]->playing) {
guschan[i]->generateSamples(&buffer[0],len);
}
}
Bit32s sample;
Bit16s * bufptr = (Bit16s *)stream;
// static Bitu showamp;
// if ((++showamp&127)==0) LOG_MSG("AutoAmp: %d",AutoAmp);
for(i=0;i<len*2;i++) {
sample=((buffer[i] >> 8)*AutoAmp)>>9;
if (sample>32767) {
sample=32767;
AutoAmp--;
} else if (sample<-32768)
{
sample=-32768;
AutoAmp--;
}
bufptr[i] = (Bit16s)(sample);
}
if(myGUS.irqenabled) {
if(IRQFifo.stackpos >= 0) {
PIC_ActivateIRQ(myGUS.irq1);
}
}
if(myGUS.timers[0].active) {
myGUS.timers[0].countdown-=(len * (Bit32u)myGUS.mupersamp);
if(!myGUS.irq.T1) {
// Expire Timer 1
if(myGUS.timers[0].countdown < 0) {
if((myGUS.TimerControl & 0x04) !=0) {
PIC_ActivateIRQ(myGUS.irq1);
}
myGUS.irq.T1 = true;
//LOG_GUS("T1 timer expire");
//myGUS.timers[0].countdown = myGUS.timers[0].setting;
}
}
}
if(myGUS.timers[1].active) {
if(!myGUS.irq.T2) {
myGUS.timers[1].countdown-=(len * (Bit32u)myGUS.mupersamp);
// Expire Timer 2
if(myGUS.timers[1].countdown < 0) {
if((myGUS.TimerControl & 0x08) !=0) {
PIC_ActivateIRQ(myGUS.irq1);
}
myGUS.irq.T2 = true;
}
}
}
}
// Generate logarithmic to linear volume conversion tables
void MakeTables(void)
{
int i;
for(i=0;i<256;i++) {
float a,b;
a = pow(2.0f,(float)(i >> 4));
b = 1.0f+((float)(i & 0xf))/(float)16;
a *= b;
a /= 16;
vol8bit[i] = (Bit16u)a;
}
for(i=0;i<4096;i++) {
float a,b;
a = pow(2.0f,(float)(i >> 8));
b = 1.0f+((float)(i & 0xff))/(float)256;
a *= b;
a /= 16;
vol16bit[i] = (Bit16u)a;
}
}
void GUS_Init(Section* sec) {
memset(&myGUS,0,sizeof(myGUS));
memset(GUSRam,0,1024*1024);
Section_prop * section=static_cast<Section_prop *>(sec);
if(!section->Get_bool("gus")) return;
myGUS.rate=section->Get_int("rate");
myGUS.portbase = section->Get_hex("base") - 0x200;
myGUS.dma1 = section->Get_int("dma1");
myGUS.dma2 = section->Get_int("dma2");
myGUS.irq1 = section->Get_int("irq1");
myGUS.irq2 = section->Get_int("irq2");
strcpy(&myGUS.ultradir[0], section->Get_string("ultradir"));
adlib_commandreg = 85;
myGUS.timers[0].active = false;
myGUS.timers[1].active = false;
memset(&myGUS.irq, 0, sizeof(myGUS.irq));
IRQFifo.stackpos = -1;
myGUS.irqenabled = false;
// We'll leave the MIDI interface to the MPU-401
// Ditto for the Joystick
// GF1 Synthesizer
IO_RegisterWriteHandler(0x302 + GUS_BASE,write_gus,IO_MB);
IO_RegisterReadHandler(0x302 + GUS_BASE,read_gus,IO_MB);
IO_RegisterWriteHandler(0x303 + GUS_BASE,write_gus,IO_MB);
IO_RegisterReadHandler(0x303 + GUS_BASE,read_gus,IO_MB);
IO_RegisterWriteHandler(0x304 + GUS_BASE,write_gus,IO_MB|IO_MW);
IO_RegisterReadHandler(0x304 + GUS_BASE,read_gus,IO_MB|IO_MW);
IO_RegisterWriteHandler(0x305 + GUS_BASE,write_gus,IO_MB);
IO_RegisterReadHandler(0x305 + GUS_BASE,read_gus,IO_MB);
IO_RegisterReadHandler(0x206 + GUS_BASE,read_gus,IO_MB);
IO_RegisterWriteHandler(0x208 + GUS_BASE,write_gus,IO_MB);
IO_RegisterReadHandler(0x208 + GUS_BASE,read_gus,IO_MB);
IO_RegisterWriteHandler(0x209 + GUS_BASE,write_gus,IO_MB);
IO_RegisterWriteHandler(0x307 + GUS_BASE,write_gus,IO_MB);
IO_RegisterReadHandler(0x307 + GUS_BASE,read_gus,IO_MB);
// Board Only
IO_RegisterWriteHandler(0x200 + GUS_BASE,write_gus,IO_MB);
IO_RegisterReadHandler(0x20A + GUS_BASE,read_gus,IO_MB);
IO_RegisterWriteHandler(0x20B + GUS_BASE,write_gus,IO_MB);
PIC_RegisterIRQ(myGUS.irq1,0,"GUS");
PIC_RegisterIRQ(myGUS.irq2,0,"GUS");
// DmaChannels[myGUS.dma1]->Register_TC_Callback(GUS_DMA_TC_Callback);
MakeTables();
int i;
for(i=0;i<=32;i++) {
guschan[i] = new GUSChannels(i);
}
// Register the Mixer CallBack
gus_chan=MIXER_AddChannel(GUS_CallBack,GUS_RATE,"GUS");
MIXER_SetMode(gus_chan,MIXER_16STEREO);
MIXER_Enable(gus_chan,false);
int portat = 0x200+GUS_BASE;
// ULTRASND=Port,DMA1,DMA2,IRQ1,IRQ2
SHELL_AddAutoexec("SET ULTRASND=%3X,%d,%d,%d,%d",portat,myGUS.dma1,myGUS.dma2,myGUS.irq1,myGUS.irq2);
SHELL_AddAutoexec("SET ULTRADIR=%s", myGUS.ultradir);
}
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